Conventional WLAN devices can establish communication connections over a number of channels, each occupying a different frequency bandwidth. To increase bandwidth efficiency, wireless standard have been developed that frequency divide an available channel to enable multi-user multiple-input multiple output (MU-MIMO) communications over the same channel.
FIG. 10 is a diagram showing transmissions according to the IEEE 802.11ax standard that includes MU-MIMO communications. FIG. 10 shows a conventional packet that can be transmitted over a channel having a bandwidth of about 20 MHz. The conventional packet can begin with a legacy preamble followed by a high efficiency (HE) preamble. Subsequently, data for different destinations can be transmitted on different resource units (RUs), which can each occupy a different portion of the channel bandwidth. Orthogonal frequency division multiple access modulation is used to transmit different data streams on the separate RUs in parallel with one another.
While MU-MIMO capabilities can make better use of available spectra, any ability to extend a communication range in a wireless device could further improve the performance of a wireless network and/or enable new applications for wireless networks.